Buggy code:
public abstract class Definer extends DefBase { private static final String ANTLIB_XML = "//antlib.xml" ; private static class ResourceStack extends ThreadLocal { public Object initialValue ( ) { } Map getStack ( ) { } } private static Definer . ResourceStack resourceStack = new Definer . ResourceStack ( ) ; private String name ; private String classname ; private File file ; private String resource ; private boolean restrict = false ; private int format = Definer . Format . PROPERTIES ; private boolean definerSet = false ; private int onError = Definer . OnError . FAIL ; private String adapter ; private String adaptTo ; private Class adapterClass ; private Class adaptToClass ; public static class OnError extends EnumeratedAttribute { public static final int FAIL = 0 ; public static final int REPORT = 1 ; public static final int IGNORE = 2 ; public static final int FAIL_ALL = 3 ; public static final String POLICY_FAIL = "fail" ; public static final String POLICY_REPORT = "report" ; public static final String POLICY_IGNORE = "ignore" ; public static final String POLICY_FAILALL = "failall" ; public OnError ( ) { } public OnError ( String value ) { } public String [ ] getValues ( ) { } } public static class Format extends EnumeratedAttribute { public static final int PROPERTIES = 0 ; public static final int XML = 1 ; public String [ ] getValues ( ) { } } protected void setRestrict ( boolean restrict ) { } public void setOnError ( Definer . OnError onError ) { } public void setFormat ( Definer . Format format ) { } public String getName ( ) { } public File getFile ( ) { } public String getResource ( ) { } public void execute ( ) throws BuildException { } public static String makeResourceFromURI ( String uri ) { } private URL fileToURL ( ) { String message = null ; if ( ! ( file . exists ( ) ) ) { message = ( "File<seq2seq4repair_space>" + ( file ) ) + "<seq2seq4repair_space>does<seq2seq4repair_space>not<seq2seq4repair_space>exist" ; } if ( ( message == null ) && ( ! ( file . isFile ( ) ) ) ) { message = ( "File<seq2seq4repair_space>" + ( file ) ) + "<seq2seq4repair_space>is<seq2seq4repair_space>not<seq2seq4repair_space>a<seq2seq4repair_space>file" ; } try { if ( message == null ) { <START_BUG> return file . toURL ( ) ; <END_BUG> } } catch ( Exception ex ) { message = ( ( "File<seq2seq4repair_space>" + ( file ) ) + "<seq2seq4repair_space>cannot<seq2seq4repair_space>use<seq2seq4repair_space>as<seq2seq4repair_space>URL:<seq2seq4repair_space>" ) + ( ex . toString ( ) ) ; } switch ( onError ) { case Definer . OnError . FAIL_ALL : throw new BuildException ( message ) ; case Definer . OnError . FAIL : case Definer . OnError . REPORT : log ( message , MSG_WARN ) ; break ; case Definer . OnError . IGNORE : log ( message , MSG_VERBOSE ) ; break ; default : break ; } return null ; } private Enumeration resourceToURLs ( ClassLoader classLoader ) { } protected void loadProperties ( ClassLoader al , URL url ) { } private void loadAntlib ( ClassLoader classLoader , URL url ) { } public void setFile ( File file ) { } public void setResource ( String res ) { } public void setAntlib ( String antlib ) { } public void setName ( String name ) { } public String getClassname ( ) { } public void setClassname ( String classname ) { } public void setAdapter ( String adapter ) { } protected void setAdapterClass ( Class adapterClass ) { } public void setAdaptTo ( String adaptTo ) { } protected void setAdaptToClass ( Class adaptToClass ) { } protected void addDefinition ( ClassLoader al , String name , String classname ) throws BuildException { } private void tooManyDefinitions ( ) { } }

Fix:
return FileUtils . getFileUtils ( ) . getFileURL ( file ) ;